Self-contained underwater buoyancy system

ABSTRACT

A self-contained underwater buoyancy system comprising a lifting assembly having separably connected upper and lower portions connected in separated condition by a pair of load lines, a fuel tank containing a monopropellant fuel and a gas generator assembly having a main body portion housing a catalyst bed which causes the monopropellant fuel to turn into a gas and a pistoltype grip with a trigger valve for controlling the flow of monopropellant fuel to the catalyst bed.

United States Patent References Cited UNITED STATES PATENTS 2,935,312 5/1960 Kilpatrick et a]. 266/23 3,471,877 10/1969 Bayles 9/8 Primary Examiner-Milton Buchler Assistant ExaminerSteven W. Weinrie'b AttorneysEdgar J. Brower and Roy Miller ABSTRACT: A self-contained underwater buoyancy system comprising a lifting assembly having separably connected upper and lower portions connected in separated condition by a pair of load lines, a fuel tank containing a monopropellant fuel and a gas generator assembly having a main body portion housing a catalyst bed which causes the monopropellant fuel to turn into a gas and a pistol-type grip with a trigger valve for controlling the flow of monopropellant fuel to the catalyst bed.

PATENTEU M3831 19m SHEET 1 or 3 INVENTOR. DONALD MILLER ROY MILLER E n- L uVlrllllrl ATTORNEY.

SELF-CONTAINED UNDERWATER BUOYANCY SYSTEM GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION The invention relates to a self-contained underwater buoyancy system adapted for use at diver depths. Heretofore, divers working in an ocean environment utilized air bottles for releasing air into duffel bags or other closed containers and CO cartridges also exhausting into a closed container for lifting loads underwater. The main disadvantage of prior devices were that they were ordinarily ineffective and the amount of gas released was not controllable. Other disadvantages were that they were not reusable and did not have a variable lift capacity.

SUMMARY OF THE INVENTION The invention comprises a self-contained underwater buoyancy system which may be handled by one or two divers and comprises a lifting assembly having a separable upper and lower portion'with a gastight expandable gas container housed therein. Load lines connect the upper and lower portion so that a load may be connected to the bottom most portion, the

gas released into the gastight member and the load lifted. Also included is a gas generator designed to release a gas into the gastight container incorporating a catalyst bed and an on-off valve which may be controlled by the operator to control the amount of monopropellant fuel which is connected to the catalyst bed. The monopropellant fuel is contained within a cylindrical fuel container having a spring-loaded piston member which is used to expel the monopropellant fuel into the catalyst bed under operator control.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cutaway of the lifting assembly;

FIG. 2 is a partial cutaway of the gas generator and a full cutaway of the fuel container; and

FIG. 3 is a cutaway of the fuel container illustrating the loading mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates the lifting assembly which comprises an upper portion and a lower portion 11 which may be formed of any suitable material such as in the present instance Fiberglas. Lower portion 11 has inlet ports designated 12 formed therein so that an inflating gas may be injected therethrough. The upper and lower portions are joined in closed positions as at 13 by a closure member 14, one portion of which is secured to the upper portion by a screw member 15 and the other portion secured to the lower portion by screw member 16.

A load eyebolt 17 is threadedly secured to the upper portion of the lifting assembly and another load eyebolt 18 is threadedly secured to the lower assembly 11. The load eyebolts are held in position by, for instance the load eyebolt 18, a washer 19 on the inner surface of the lower portion 11, washer 20 on the outer surface and nuts 21 and 22 engaging the washers 20 and 19 respectively. The upper load eyebolt 17 is held in position in the same fashion.

Load lines 23 and 24 connect the upper portion 10 and the lower portion 11. Load line 23 is connected to the upper portion by an eyebolt 25 and to the lower portion by another eyebolt 26. The same configuration applies for load line 24.

A gastight container 27 is contained within said lifting as sembly and is supported in uninflated condition on a retainer plate 28 having holes there adapted to fit within said lower portion 11. The bottom end of the lifting container 27 is secured by screws 29 to the lower portion 11 of the lifting assembly while the upper end of the lifiing container 27 is secured to the upper portion of the lifting assembly by screws 70.

A gas generator generally indicated at 30 in FIG. 2 and a fuel container generally indicated at 31 forms the means whereby a gas is generated which may be used to inflate the gastight container 27 of FIG. 1. The gas generator 30 comprises a main body portion 32 filled with a syntactic foam (micron-sized hollow glass, ceramic or plastic spheres in a plastic binder) generally indicated at 33 having holes drilled therethrough, generally indicated at 34. The holes are used to allow cooling water to contact and cool a catalyst bed 35.

The catalyst bed generally indicated at 35 is contained within said main body portion. The catalyst bed comprises Shell 405 catalyst and is contained between an inlet plate 36 having holes therethrough and an outlet plate 37 also having holes therethrough. The catalyst bed is threadedly secured by screws 38 to a mounting plate 39 contained within the main body portion.

One end of the main body portion terminates in an end plate 40 while the exhaust end of the main body portion is terminated by end plate 41. In contact with exhaust end plate 41 is a hot gas check valve 66 which also is in open communication with the exhaust plate 37. At'the other end of the main body portion an inlet check valve 67 is in communication with the end plate 40 and also in open communication with the inlet plate 36.

A pistol grip 42 having a portion at 43 adapted to fit in the divers hand is suitably secured to the end plate 40. The pistol grip 43 contains an on/off trigger valve 44 which controls the opening and closing of a monopropellant feed line at 45.

An exhaust tube 46 terminated by an exhaust flapper valve 47 is suitably secured to the exhaust end plate 41.

Fuel container 31 is connected to the gas generator 30 by means of a flexline 48 which has an operator controlled on/off valve 49 connected in series therein. The flexline 48 terminates at the lower end of the fuel container 31 in an outlet port connector which is threadedly inserted into female fitting 65 in lower end plate 51. The lower end plate is welded to a cylindrical fuel container 52 which is terminated at its upper end by an upper end plate 53 threadedly secured therein. The fuel container and end plates may be formed of any suitable material which is resistant to the ocean environment and compatible with hydrazine such as for instance stainless steel. The various portions of the gas generator, end plates, grip, etc. are also formed from stainless steel.

A piston member 54 in O-ring sealing relationship with the internal walls of the cylinder 52 is adapted to slide up and down therein. The lower end of piston 54 abuts a monopropellant hydrazine fuel (in loaded condition) generally indicated at 55. The upper side of piston 54 abuts the lower end of a spring-loading member 56 which in turn has its upper end abutting the upper end plate 53.

FIG. 3 illustrates the fuel container 31 in unloaded condition with the apparatus used to load the container with fuel in position. The apparatus comprises a handwheel 60 fixedly engaging a screw-threaded member 61, an internally threaded member 62 which abuts the upper end cap 53, and a lower terminating member 63 which is threadedly secured by screws 64 to the piston 54.

The fuel container 31 is loaded by connecting a source of liquid hydrazine to the valve 49 which is connected to the valve 49 which is connected to the fuel container 31 with a stainless steel line at inlet port 65. When the handwheel 60 is turned counterclockwise the piston member 54 is caused to travel toward the upper end plate 53. This action draws hydrazine into the body of the fuel tank 52. When the fuel tank is loaded the hand valve 49 is closed and because the liquid hydrazine is incompressible, when the handwheel 60 is turned in the clockwise direction, the threaded member 62 lifts off the upper end plate 53. The screw member 61 is then disengaged from the lower terminating member 63 by sliding it out of the open slot.

ln operation, a diver or divers take the fuel container, monopropellant gas generator and lifting assembly-to the operating depth. The lifting assembly is attached to the load 54. The hand valve 49 is opened by the diverand the fuel is I then transferred by the flexline 48 to the control valve 45. When the trigger 44 is squeezed the fuel is forced through the fuel check valve 67 to the catalyst bed 35. The catalyst bed causes the fuel to decompose and thereby produce gas (N,H,NH) which, in turn, passes through the hot gas check valve 66 and through the exhaust tube 46 thereby opening the exhaust flapper valve. The exhaust tube 46 is inserted into one of the lower openings 12 in the lower portion of the lifting assembly thereby causing the gas to exhaust into the lifting container 27 through the holes in the retainer plate 28.

The trigger 44 is depressed until the desired amount of lift is acquired at which point the trigger is released and the flow of the monopropellant hydrazine is stopped thereby stopping the gas production.

The systemillustrated will lift a load of 1,000 pounds at a depth of 150 feet or a number of smaller loads from the same depth.

The system lift capabilities are dependent upon the size of the lifting container and fuel capacity. The self-contained lifting assembly is readily adaptable to one or two man operation and requires no explosive devices, no lines from the surface, no expendable parts, no electrical devices and no nitrogen pressure is needed to load the fuel tank. in addition, the system operates at a very low pressure and has a variable lift capability. Furthermore, if it is desired to move objects around on the ocean floor only enough gas may be generated to cause the objects to become neutrally buoyant through the use of the lifting assembly.

What is claimed is:

l. A self-contained underwater buoyancy system comprising in combination;

a lifting assembly having upper and lower portions;

said upper and lower portions being separably connected;

an extensible gas container housed within said upper and lower portions;

said lower portion of the assembly having inlet ports adapted to receive an outlet nozzle means;

gas generator means adapted to be carried by a diver underwater;

said gas generator means comprising a gunlike member;

a portion of the gunlike member being adapted to fit in a divers hand;

output nozzle means on said gas generator means adapted to be inserted into at least one of the inlet ports in the lower portion of the assembly so that gas flowing from the nozzle causes said gas container to expand;

a fuel supply operably connected to said gas generator means; and

a triggerlike member on the gas generator means for controlling the flow of fuel into the gas generator means.

2. A self-contained underwater buoyancy system as set forth in claim 1 and further including;

load-lifting members connecting said upper and lower portions of the lifting assembly such that when the upper and lower portion are separated the load-lifting means connect the said two portions.

3. A self-contained underwater buoyancy system as set forth in claim 1 wherein;

said fuel is hydrazine; and said gas generator means includes a catalyst adapted to cause said hydrazine fuel to become a gas. 4. A self-contained underwater buoyancy system as set forth in claim 1 wherein said fuel comprises a monopropellant.

5. A self-contained underwater buoyancy system as set forth in claim 1 wherein;

said fuel supply comprises a cylinder having an outlet portion; a piston member contained within said cylinder in sealing relationship with the cylinder wall; a spring-loading member between one side of said piston member and one end of the cylinder opposite the inlet end; and fuel contained within said remaining portion of said fuel container. 

1. A self-contained underwater buoyancy system comprising in combination; a lifting assembly having upper and lower portions; said upper and lower portions being separably connected; an extensible gas container housed within said upper and lower portions; said lower portion of the assembly having inlet ports adapted to receive an outlet nozzle means; gas generator means adapted to be carried by a diver underwater; said gas generator means comprising a gunlike member; a portion of the gunlike member being adapted to fit in a diver''s hand; output nozzle means on said gas generator means adapted to be inserted into at least one of the inlet ports in the lower portion of the assembly so that gas flowing from the nozzle causes said gas container to expand; a fuel supply operably connected to said gas generator means; and a triggerlike member on the gas generator means for controlLing the flow of fuel into the gas generator means.
 2. A self-contained underwater buoyancy system as set forth in claim 1 and further including; load-lifting members connecting said upper and lower portions of the lifting assembly such that when the upper and lower portion are separated the load-lifting means connect the said two portions.
 3. A self-contained underwater buoyancy system as set forth in claim 1 wherein; said fuel is hydrazine; and said gas generator means includes a catalyst adapted to cause said hydrazine fuel to become a gas.
 4. A self-contained underwater buoyancy system as set forth in claim 1 wherein said fuel comprises a monopropellant.
 5. A self-contained underwater buoyancy system as set forth in claim 1 wherein; said fuel supply comprises a cylinder having an outlet portion; a piston member contained within said cylinder in sealing relationship with the cylinder wall; a spring-loading member between one side of said piston member and one end of the cylinder opposite the inlet end; and fuel contained within said remaining portion of said fuel container. 